Termite resistance of DMDHEU treated wood

Transcription

1 IRG 2008 Termite resistance of DMDHEU treated wood H. Militz, S. Schaffert, B. Peters, C. Fitzgerald

2 Content Wood modification technology State-of-art DMDHEU technology Test set up Results From now on?

3 Wood modification technology in Europe Processes on market: Heat treatment (several) Acetylation (Titan Wood Accoya ) Furfurylation (Kebony) Parafins/Waxes DMDHEU Belmadur

4 Polymer treatment of wood: processes wood impregnation drying/ reaction modified wood N NR 2 N HOCH 2 N O N CH 2 OH HO O R 2 N N NR 2 R = H, CH 2 OH, CH 2 OCH 3 HO OH

5 Main focus last period: upscaling processes

6 Different structures of textile modifiers O O HOCH 2 N N CH 2 OH RROH 1 2 C CH N N 2 ORR 2 HO H 3 C HO N O N OH DMDHEU dimethylol-dihydroxy-ethyleneurea OH CH 3 DHDMI dihydroxy-dimethyl-imidazolidinone HRO HOCH 2 NH C O ORH NH R 1 = H oder CH 3 R 2 = H oder CH 3 mdmdheu methylated (modified) DMDHEU DMU dimethylol-urea CH 2 OH

7 Additives catalysts Co-modifiers Hydrophobing agents O dyes HOCH 2 N N CH 2 OH Pot stabilisation HO OH Formaldehydscavangers UVprotection further

8 Einleitung Softwood structure (Harrington) Reaction with cell wall Filling lumina Füllen der Zelllumina

9 Belmadur ; BASF AG, D Production: Becker Belmadur Shaped veneer products Hamberger Parkett flooring Business modell Licence technology Properties Depending on end-use

10 Wood properties Dimensional stability (ASE 65%) Durability (class 1-2) Weathering resistance Hardness (increase up to 200%) Brittleness Termite resistance? Trials in Portugal (Lina Nunes) Tropical conditions?

11 Serious wood attackers, these termites... says Mr. Jack Norton, DPI, QLD

12 Sample size: Wood samples and wood species 25x70x150or 190mm 3 Wood species: Scots pine (Pinus sylvestris) from Germany Beech (Fagus sylvatica) from Germany Slash pine (Pinus eliottii) from QLD Spotted gum (Corymbia maculata) from QLD

13 Treatments Untreated controls Hazard class 3 control CCA treated pine from DIY Two levels DMDHEU Level A: 1.3M Level B: 2.3M

14 MATERIALS AND METHODS Field Trials: Tropic of Townsville Capricorn Esk Indooroopilly

15 Modification process Treatment with aqueous solution Curing/drying at approx. 120 C In semi-production plant BASF

16 Trial 1: field test ESK (brick assembly method) Trial 1: Esk (near Brisbane) Coptotermes acinaciformis Brick assembly method (Australasian Wood preservation Committee 2007) 6 L lunch boxes Duration: 47 weeks

17 Trial 3: field test ROWES BAY/ TOWNSVILLE (brick assembly method) Trial 3: Rowes Bay/ Townsville Mastotermes darwiniensis Brick assembly method (Australasian Wood preservation Committee 2007) 6 L lunch boxes Duration: 47 weeks

18 Test field Esk (trial 1)

19 Test fields Trial 2: Indooropilly DPI Coptotermes acinaciformis 240 L rubbish bins Duration: 52 weeks

20 trial 2 bin test

21 Visual rating Evaluation scheme (adapted from AWPA) Damage 10 None, sound 9 Light damage, surface nibbles 7 Moderate damage, noticeable surface penetration 4 Heavy damage 0 Completely destroyed Visual assessment Weight loss Strength loss Experimental design / statistics: see paper

22 Lunch box test trail 1 Esk, Coptotermes

23 Mass loss [%] in termite trials (trial 1)

24 Results trial 1 ESK Mass loss of feeder specimens 62% Even with heartwood percentage! Adequate feeding pressure Mean mass loss of all specimens/ concentrations: 2.7% = good protection by DMDHEU

25 Coptotermes soldiers and workers in bin test

26 Mass loss [%] in termite trial 2 bin

27 Results trial 2 bin test Indooroopilly, Coptotermes Mass loss feeder specimens: 68% Adequate feeding pressure Good protection by DMDHEU Marginal influence of timber species No significant differences between DM concentrations

28 Mass loss [%] in termite trials (trial 3)

29 Mastotermes Mass loss feeder specimens: 76% Adequate feeding pressure Good protection of pine by DMDHEU No protection of beech! Trend: higher conc. gives better protection

30 Discussion/conclusions: Test methodology Trials 2007/08: drought in QLD: Even though attack adequate Resistance of Pinus sylvestris heartwood feeder blocks Good accord between visual rating and mass loss Results with Coptotermes in field Esk and bin test in Indooroopilly comparable Fast attack in comparison to Europe 32 weeks in field: 80% w.l.

31 Mass loss [%] in termite trials (trials 1-3)

32 Discussion/ Conclusions: effectiveness of DMDHEU Treated Pine very good resistance against Coptotermes good resistance against Mastotermes Treated Beech good resistance against Coptotermes No resistance against Mastotermes C/N levels were ok

33 Discussion/conclusions: further research Lower levels DMDHEU to be tested against Coptotermes Higher levels to be tested against Mastotermes Other/ more wood species to be tested Effect beech?!

34 Thanks to: Hard workers (part 1)

35 Thanks to: Hard workers (part 2)

36 Thanks to: The whole team at DPI/ QLD BASF for support